• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.04a
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• pp.147-147
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• 1993

All types of dynamic excitation, periodical, pulse or transient in vertical, horizontal or all three directions can be effectively reduced by vibration isolation systems. Typical elements for vibration isolation control are spring units consisting of a group of helical compression springs. In all cases of shock, transient or random excitation energy absorbing dampers have to be added to the spring units in order to reduce system response in the frequency range near the natural frequency of the isolation system. The same isolation system of spring units and viscos-dampers has been used since 1979 for passive protection of buildings and structures has been proved to by very advantageous for vibration and structure borne noise control. Not only because of high vertical flexibility of the spring units, compared for example with typical rubber or neoprene mounts out also because of the horizontal of flexibility, which can be adapted by modifying the spring dimensions to nearly every requirement. It is just normal to use the same basic elements for passive isolation as for active isolation.

• KIEAE Journal
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• v.7 no.1
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• pp.95-100
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• 2007

In apartment houses, said to be similar to a typical housing form, every household share the walls and floors. Many problems inevitably accompany such as an arrangement, as noise and vibration are shared among households. When investigating the percentage of apartment resident's dissatisfaction with housing environments, discontent due to noise ranks the highest. Among many different kinds of noises, noise such as floor crashing sounds show the highest indication rate in the residents' comparison of discontent. Therefore, it is the practice of insulating against noises such as floor crashing sounds that improves the apartment house environments. The factors influencing the floor impact sound insulation include floor finishing materials, shock absorbing floors (slabs included), and ceiling structures. The ceilings of the apartment houses, currently built in Korea, are set up with lower parts of slabs and paper finishing, or with double floors for protecting against floor impact sounds in order to improve the sound insulating performance. The most common the method of ceiling structure construction consists of 'wood boarded frames +Gypsum boards + ceiling papers', which is called the wood boarded frame method. This study aimed to measures and evaluates floor impact sound insulation by which the ceiling space are widened according to suppression system is added in apartment house ceiling structure.

• Korean Journal of Applied Biomechanics
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• v.23 no.1
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• pp.63-76
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• 2013

The purpose of this study was to investigate the effects of knee joint muscle fatigue and overweight on the angular displacement and moments of the lower limb joints during landing. Written informed consent forms, which were approved by the human subject research and review committee at Dong-A University, were provided to all subjects. The subjects who participated in this study were divided into 2 groups: a normal weight group and an overweight group, consisting of 15 young women each. The knee joint muscle fatigue during landing was found to increase the dynamic stability by minimizing the movements of the coronal and horizontal planes and maintaining a more neutral position to protect the knee. The effect of body weight during landing was better in the normal weight group than in the overweight group, with the lower limbs performing their shock-absorbing function in an efficient manner through increased sagittal movement. Therefore, accumulated fatigue of knee joint muscles or overweight may be highly correlated with the increase in the incidence of injury during landing after jumping, descending stairs, and downhill walking.

• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.172-179
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• 2014

This research suggests that the regulation, design and improvement of domestic and international ambulances so that make the basis for the future ambulance in Korea. It is true that the diversification of current disasters, increasing elderly population, the increase in emergency patients, due to the lack of effective transfer system, emergency vehicle's performance problem, and the aging of ambulances cause have difficulty in providing effective emergency services in domestic country. Therefore, in order to improve the effectiveness of ambulance, the history of ambulance, other relevant provisions include international, design and directions to be improved were investigated, and also research directions of the ambulance are suggested in domestic country. In this research, suggests the following conclusions to improve domestic ambulance 1. Through standardization of the spacing and location of an ambulance is needed to maximize the treatment room. 2. The interior of the ambulance design for hygiene and infection control should be included. 3. Stretcher and equipment are designed to be fitted to each other should be standardized. 4. Especially during transfer maintain the road, noise, vibration, and shock-absorbing function to emphasize the importance. 5. The improvement of ergonomic design is necessary for the possibility of applying to many people.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.459-467
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• 2019

The landing gear is a component that requires a high degree of safety to protect the lives of rotary-wing aircraft and boarding personnel, absorbing the impact on transfer/landing and supporting the fuselage during taxiing and mooring on the ground. In particular, the wheel landing gear supporting the aircraft fuselage absorbs most of the shock from the ground through the shock absorber and tires. This ensures the safety of the pilot on board the aircraft and satisfies the operational capability of the soldiers between missions. During the operation of a rotary-wing aircraft, a number of piston pins, which are a component of the right main wheel landing gear, were found to be broken. Therefore, this study examined the root cause of the piston pin crack phenomenon found in the main wheel landing gear. For this purpose, various causes were identified from fracture surface analysis of a flight test. In particular, the possibility of cracking was analyzed based on the influence on the fastening torque with the drag beam component applied to the piston pin at the time of development. This ensures the fatigue life and structural integrity.

• Korean Institute of Interior Design Journal
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• v.23 no.6
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• pp.178-186
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• 2014

Recently, a lower levels space has turned into a mediating space where people can experience urban spaces directly and it has revitalized communication between the city and company and also it has changed itself newly. In addition, this space which is connecting interior and exterior spaces of company's buildings can attract people living in the downtown as shock-absorbing and transitional space and it is getting more important part in urban context these days. Through case studies of corporate office space planning characteristics derived lower levels and to provide direction for the lower levels of the corporate office space planning purposes of the present study. Therefore, I establish the concept of the public good corporate office space and transition space, the concept of transition through the first Theoretical Methods. I investigate the properties of the transition area is used as the target for completion of the current construction culture destination since 2000, winning the corporate office, I have been talking about the characteristics of the corporate office along the lower part of the last PPS assessment criteria to apply to the building. PPS by applying an assessment factor can be derived for building enterprise case studies and analysis of the results the following conclusions about the use of publicity and transition space. First, lower levels of corporate office space had been applied to the use and activity in a very important project characteristics. Second, corporate office space, lower levels of access and linkages are important. Finally, in terms of public characteristics transition space is a important characteristic for low-rise space of headquarter buildings.

• Fashion & Textile Research Journal
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• v.16 no.6
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• pp.1001-1007
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• 2014

We surveyed the wearing characteristics of hip protectors. The problems of existing hip protectors were identified and the directions for improvement were presented. The evaluation of wearing characteristics was conducted on the 100 elderly women (60 to 85 years) with 5 types of hip protector. The questionnaire was composed of history and characteristics on falling, hip protector acceptance, preference, use characteristics and improvement requirements. The result of wearing characteristic evaluation indicated that 52% of the subject experienced falling in winter. Incidents resulting from falling occurred: outdoors (74.5%), bathroom (10.9%), and kitchen (5.5%). Body parts to be protected were in several areas: 35.6% for lumbar, 26.9% for hip joint, and 15% for hip bone. Participants prefer a belt B type design at a rate of 56.9% because it provided a sense of stability by clinging to the body and upholding the waist. Belt B type was the most appropriate in terms of fit, allowance, mobility, and design except pad thickness. To reduce the risk of hip fracture, hip protector needs to be designed in consideration of user's type of fall and body shape. The pattern and size of a hip protector has to be improved in regards to the amount of discomfort. An objective evaluation is needed for the ergonomic design of a hip protector based on and analysis of 3D body image of the elderly and the shock-absorbing quality of pad.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.225-229
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• 2020

In this study, the deformation and stress on each model was analyzed and the strength was compared with each other when the impacts on a total of four smart phone models was given. Models B and D with cases can be seen to have less deformation and stress than models A and C without cases. The models including the case have higher masses than the models without the case. So, the deformation and stress can be reduced by absorbing the impact force. In addition, the masses of models C and D are smaller than models A and B, but the stresses and deformations are seen to be smaller. If a case specialized for edge protection is chosen and designed when manufacturing a smart-phone in order to absorb the shock while weighing less, it is thought to improve the strength of the smart-phone and increase the durability. And it is seen that this study is adequate at the efficient design with durability of smart phone case practically and the aesthetic convergence of smart phone.

• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.498-502
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• 2010

Aluminium titanate($Al_2TiO_5$) has extremely anisotropic thermal expansion properties in single crystals, and polycrystalline material spontaneously microcracks in the cooling step after sintering process. These fine intergranular cracks limit the strength of the material, but provide an effective mechanism for absorbing strain energy during thermal shock and preventing catastrophic crack propagation. Furthermore, since machinable BN-ceramics used as an insulating substrate in current micro-electronic industry are very expensive, the development of new low-cost machinable substrate ceramics are consistently required. Therefore, cheap $Al_2TiO_5$-machinable ceramics was studied for the replacement of BN ceramics. $Al_2O_3-Al_2TiO_5$ ceramic composite was fabricated via in-situ reaction sintering. $Al_2O_3$ and $TiO_2$ powders were mixed with various mol-ratio and sintered at 1400 to $1600^{\circ}C$ for 1 h. Density, hardness and strength of sintered ceramics were systematically measured. Phase analysis and microstructures were observed by XRD and SEM, respectively. Machinability of each specimens was tested by micro-hole machining. The results of research showed that the $Al_2TiO_5$-composites could be used for low-cost machinable ceramics.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.3
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• pp.49-55
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• 2012

Even though corrugated boards are the most common packaging materials for agricultural products, conventional corrugated boards are not able to maintain the freshness of agricultural products. In order to overcome the limitations of conventional corrugated boards, a new hybrid corrugated board-composed of linerboard, a corrugating medium, and non-woven fabric-was designed to possess antibacterial, high porous and shock-absorbing properties. In this study, we compared the physical properties of non-woven fabric to those of the base papers of conventional corrugated boards and developed a new adhesive system as a first step toward manufacturing the hybrid corrugated board. We found that the non-woven fabric, which had relatively high elongation, was applicable in the corrugated board process, and that the manufacturing conditions must be controlled in order to prevent the break of the non-woven fabric. The mixture of starch and styrene-butadiene (SB) latex showed high adhesive strength, but the addition level of SB latex should not exceed 30% in starch solution.